Socket for electric lamps.



G. C. KNAUF-F.

v SOCKET FOR ELECTRIC LAMPS.

APPLIGATION FILED MAY 26, 1913.

1,090,630. y Patented Mar. 17, 1914 GEORGE c. KNAUFF. or crrrcAGo, ILLINOIS.

' SOCKET FOR ELETRIC'LAMPS.

Speccationof Letters Patent.

Patented Mar. 17, 1914.

Application led May 26, 1913. u Serial No. 769,948.

To all whom it may concern ,i

Beit known that I, GEonGE C. KNAUFF, citizen-of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Sockets for Electric Lamps; and I do hereby declare the following to be a full,- clear, and exact description of the'invention, such as will enable others skilled in the art towhich it appertains to make and use the same.

My invention relates to lamp sockets and more particularly to sockets having one terminal 'grounded to the casing so as 'to carry -the currents from 'the casing to the outer shell of the lamp base, to which shell one end ofv the-filament ofthe lamp is connected.

,Owing to variations in the sizes of the commercial brass tubing used for making the shells of thelamp bases and the casings of the sockets, it has not been feasibleto obtain a close interitting of the said shell and casing. Consequently, the lamps used with sockets of this class are usually held firmly only at the projections, upon the lamp bases which are generally interlocked with bayonet catch formations upon the socket casings, and are free to rock somewhat about these projections Vas pivots.- In practice, the

vibration to which such-lamps and sockets are sub 'ected, articularly when used upon automo iles, o en causes the lamps' to impact against the socket casings with suilicient force to break their laments. Moreover, the contact between the projections upon the lamp base'and the notched portions o the slots in the socketcasing is not always j adequate for carrying the current to the {ila-- ment of the lamp.

One object of my invention is to equip the casing of the socket with spring fingers adapted to contact with the sides of the rlamp base so as to carry the current from the casing to one terminal of] the lamp.

Another object is to 'so position the points.

ofengagement of the spring ngers with the lamp base as to hold the lamp ,against lateral motion relative' to the casing.

The socket of -my invention is particularly adapted for coaction at one end with a lamp having a single central terminal and at its other end with a wire-carrying plug of the type described in my copending application of even date herewith, Serial No. 7 69,947 and is shown in this embodiment in the accompanying drawings.

' ing body 2 which is secured to the casing by a transverse screw 3. Axially mounted within the insulating body 2 is a cylinder 4l having plungers 5 and 6 projecting through perforated caps 7 at the opposite ends of the cylinder, these plungers being continuously pressed outwardly by a spring 8 interposed therebetween. The casing 1 has at each end diametrically opposite slots 9 terminating in enlargements 10 serving as seats for lateral projections 11 upon lthe met-al shell 12 of the base of the lamp used with the socket, the slots 9 serving to guide the said projections to their said seats the said seating of the projections affording a pivotal coupling between the casing and the lamp.

The lamp-engaging end of thesocket cas ing also has fingers 13 punched from the same,'these lingers being preferably diametrically opposite each other and circumferenn tially intermediate the slots 9, or at right angles to the said slots. A part end of each finger 13 is bent inwardly of the casing,` so as to slidingly engage the shell 12 of the lamp base when the latter is being inserted into, or withdrawn from, the end of the casing. The casing being of spring metal, the

subjected to vibration.` By placingthebearing portions 14 of the, fingers moreendward of the casing than the notches 10 with which the projections interlock, I enable .the ngers to exert a considerable pressure upon the sides vof the casing, thereby giving an. effective lateral supportto the lamp. Moreover, since one terminal of the circuit is grounded to the casing of theV socket when the latter is in use, the spring fingers will car the current to the metal shell 12 which orms one terminal of the lamp, While the plunger 5 connects the other terminal of the circuit to the axially disposed terminal 1 5 of the lamp. f

Instead of forming the spring fingers at the very end of the casing 1, as in Figs. 1, 2 and 3, they may be positioned'somewhat back from the end of the casing, as in Fig. 4. Likewise, their fixed ends may be nearer to the end of the socket than their free ends, as in Fig. -5-, although I prefer the arrangement of Fig. -1- or Fig. -4 as bringing the points of engagement of the fingers and the lamp base considerably more endWard than'the notches 10.

y I claim as new and desire to cover by Letters Patent:

l. In a socket for a lamp having its base equippedwith a cylindrical contact shell and diametrically opposite projections upon said shell, a casing having one end larger in bore than the diameter of said shell, the said casing equipped with notched slots receiving the said projections respectively when the shell is inserted in the said endof the casing, the notches of said slots interlocking with the vsaid projections to pivotally couple the lamp to the casing; and spring fingers bent from the said casing at points substantially at right angles to the common axis of the said projections and bearing against the said shell, the resiliency of the said fingers causing the latter to hold the adjacent parts of the said shell out of contact with the end portion of the said casing and to prevent a forcible impact of the shell against the casing upon relative motion of the lamp and casing about their said pivotal coupling.

2. In a socket for a lamp having its base equipped with a cylindrical contact shell and diametrically` opposite projections upon said shell, acasing connected to one terminal of a circuit and having one end larger in bore than the diameter of said shell, the said casing equipped Withnotched slots receiving the said projections respectively when the shell is inserted in the said end of the casing, the notches of said slots'interlocking with the said projections to pivotally couple the lamp to the casing; and spring fingers bent from the said casingA at points substantially at right angles to the common axis of the said projections and bearing against the said shell to carry current from the casing to the shell'the resiliency-of the said fingers caus- ALBERT SGHEIBLE, G. M. NEVILLE. 

